composition, Polishers' Supplies. Greene, Tweed & Co., New York city.
_Catarrh Cured._
A clergyman, after years of suffering from that loathsome disease,
catarrh, and vainly trying every known remedy, at last found a
prescription which completely cured and saved him from death. Any
sufferer from this dreadful disease sending a self-addressed stamped
envelope to Dr. Lawrence, 212 East 9th St., New York, will receive the
recipe free of charge.
Lick Telescope and all smaller sizes built by Warner & Swasey,
Cleveland, Ohio.
Send for catalogue of Scientific Books for sale by Munn & Co., 361
Broadway, N. Y. Free on application.
Notes & Queries
HINTS TO CORRESPONDENTS.
=Names and Address= must accompany all letters, or no attention will be
paid thereto. This is for our information, and not for publication.
=References= to former articles or answers should give date of paper
and page or number of question.
=Inquiries= not answered in reasonable time should be repeated;
correspondents will bear in mind that some answers require not a little
research, and, though we endeavor to reply to all, either by letter or
in this department, each must take his turn.
=Special Written Information= on matters of personal rather than
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Price 10 cents each.
=Books= referred to promptly supplied on receipt of price.
=Minerals= sent for examination should be distinctly marked or labeled.
* * * * *
(1) L. M. W. asks (1) a receipt for marsh mallows, as made by
confectioners. A. Dissolve one-half pound of gum arabic in one pint
of water, strain and add one half pound of fine sugar, and place over
the fire, stirring constantly until the sirup is dissolved, and all of
the consistency of honey. Add gradually the whites of four eggs well
beaten. Stir the mixture until it becomes somewhat thin and does not
adhere to the finger. Flavor to taste and pour into a tin slightly
dusted with powdered starch, and when cool divide into small squares.
2. The title of a good veterinary journal. A. _American Veterinary
Review_, New York. 3. The formula for a spavin cure? A. Take of sweet
oil 4 ounces, spirits of turpentine 2 ounces, oil of stone 1 ounce.
Mix and apply three times per day. 4. A receipt for a wash that will
prevent rabbits from injuring the bark of fruit trees. A. We know of
nothing good for this purpose.
(2) A. L. K. asks how common fat can be rendered into tallow in an
open kettle. A. Keep the tallow melted for some time, along with about
two per cent of sulphuric acid largely diluted with water, employing
constant agitation, and allowing the whole to cool slowly; then remelt
the cake with a large quantity of hot water, and wash well.
(3) W. C. B. asks about the process and kind of machinery used in
preparing raw sienna for paint. A. The raw sienna is thrown directly on
the hearth of a reverberatory furnace and kept thoroughly raked until
it assumes a proper color. Very little, if any, sienna is known to be
burnt in this country.
(4) W. M. M. asks for some transparent paint suitable to paint on
tracing muslin. A. You must use a transparent varnish such as the
following: Dissolve 30 parts of copal and 2 parts of camphor in 120
parts of oil of turpentine and 30 parts of oil of lavender. Use lakes,
gamboge, Prussian blue, and the other transparent colors, mixed with
the vehicle.
(5) S. S. asks a receipt for black heads. A. Cover the parts afflicted
with a pomade consisting of kaolin 4 parts, glycerine 3 parts, acetic
acid 2 parts, with the addition of a small quantity of ethereal oil.
See SUPPLEMENT, No. 542.
(6) W. L. asks (1) a cure for frost bitten feet. A. For frost bites,
rub the affected parts with pure oil of peppermint. It will also
prevent the after effect of chilblains. Care should be taken to use
only the pure oil, and not the essence of peppermint, as the essence
will not have the desired effect. 2. How plate glass is made. A. See
SCIENTIFIC AMERICAN SUPPLEMENT, No. 340.
(7) A. T.--Hard rubber is a very good insulator; gutta percha is also
very good, and can be softened by boiling water and given any desired
shape.
(8) J. H. S. wants a good receipt to prevent hair coming out. A. Scald
black tea, 2 ounces, with 1 gallon of boiling water, strain, and add 3
ounces glycerine, tincture cantharides ½ ounce, bay rum 1 quart. Mix
well and perfume. This is a good preparation for frequent use in its
effect both on the scalp and hair, but neither will be kept in good
condition without care and attention to general health. See articles in
SUPPLEMENTS, 102, 388, 396.
(9) A. H. asks the size of steel wire rope necessary to suspend a
weight of 16,000 pounds, each end of the rope being fastened 1,600
yards apart, the weight to travel from one end to the other on the
rope. A. The scheme of so long a span carrying a load is impracticable.
A span of 4,800 feet will nearly absorb the margin of safety by its own
weight, depending upon the amount of deflection that could be allowed
in the catenary curve. The largest steel cables that are made, 2⅝
inches, weigh 13 pounds per foot, or over 31 net tons for your span;
with a deflection of one twenty-fifth, or nearly 200 feet, the tension
would be 3¼ times the weight, or 254,800 pounds, while the ultimate
strength is but 400,000 pounds.
(10) G. A. L. asks: Why will a brake on the hind end of a train of
cars hold more than a brake set ahead of it on train? A. We do not know
that it is so. It is possibly a fancy.
(11) A. K. H. asks: Will hot air cool off by sending it rapidly through
a wooden tube 300 or 400 feet long? If so, how much? A. Yes, slightly.
An iron pipe is better if you wish to cool the air. How much the air
will be cooled will depend on initial temperature and the temperature
of the conductor and surrounding air.
(12) H. H. writes: I have large quantities of iron and steel to pickle,
or, in other words, to clean. I use oil of vitriol, which is expensive
and dangerous. Is there an acid that would be cheaper and at the
same time as effective? A. We know of nothing cheaper or better than
sulphuric acid for pickling castings. The most economical method, as
practiced here, is found in the hot bath, a tub lined with lead, or if
of small requirement a stone pot. Water 5 to 8 parts, acid 1 part. Boil
the work in the acid bath for a few minutes, then rinse in hot water.
There is no danger if properly managed. For wrought iron and steel,
use hydrochloric acid and water.
(13) W. F. E. asks: 1. How are bath bricks made? A. Bath bricks are
found native as minerals, and are imported from England. 2. How are
papier mache ornaments moulded, and where can I procure a work on the
subject? A. We can send you Spons' "Workshop Receipts" for $2.00, first
series, which contains full information on papier mache. See also
various articles in SCIENTIFIC AMERICAN SUPPLEMENT on the
technology of the paper trade.
(14) W. M. S. asks how to make liquid glue. A. Take a wide mouthed
bottle, and dissolve in it 8 ounces best glue in ½ pint water, by
setting it in a vessel of water, and heating until dissolved. Then add
slowly 2½ ounces strong nitric acid 36° Baume, stirring all the while.
Effervescence takes place, with generation of fumes. When all the acid
has been added, the liquid is allowed to cool. Keep it well corked, and
it will be ready for use at any time.
(15) E. H. F. asks what preparation steam laundries use to make their
goods so stiff and have such a fine gloss, and how is it used, and,
if used with starch, is hot or cold starch used? A. Melt 2½ pounds
of the very best A 1 paraffine wax over a slow fire. When liquefied,
remove from the fire and stir in 100 drops oil of citronella. Have a
lot of round new pie tins, clean and nice; place them on a level table,
coat them slightly with sweet oil, and pour about six tablespoonfuls
of the enamel into each tin. The pan may be floated in water to cool
the contents sufficiently to permit the mixture to be cut or stamped
out with a tin cutter into small cakes about the size of a peppermint
lozenge. Two of these cakes added to each pint of starch will cause the
smoothing iron to impart the finest possible finish to muslin or linen,
besides perfuming the clothes.
(16) J. T. M., Jr., asks for a tempering liquid for tempering a flat
coiled spring, ⅛ of an inch thick, 1½ inches wide, 20 feet long,
without drawing the temper. A. You can get a spring temper in the
hardening bath. Harden in water or oil and draw temper in an iron pan
of linseed oil at boiling temperature.
(17) C. E. H. writes: I have nearly 1,000 feet of out-door steam
pipe carried in elevated wooden boxes. What is a good and cheap pipe
covering to prevent loss of heat? A. Pulverized charcoal or sawdust
makes a good cheap insulation for steam pipes. The boxes should be
large enough to allow 2 inches clearance all around the pipe, the
latter to be retained in position by cleats. Boxes should be tight
enough to prevent circulation of air. Tar the outside to make weather
proof.
(18) B. L. asks: 1. Is there any method for removing rust stains from
white cloth or linen? A. See the table in SCIENTIFIC AMERICAN
SUPPLEMENT No. 158, for the "Removal of Stains and Grease Spots."
2. Is there any book showing how to work out chemical problems, and
giving answer in the back of the book? A. Professor J. P. Cooke's
"Chemical Problems and Reactions" can be sent you postpaid for $1.
(19) D. B. wants a receipt for a dark cherry stain for a white pine
floor. A. Use rain water 3 quarts, annatto 4 ounces; boil in a copper
kettle till the annatto is dissolved, then put in a piece of potash the
size of a walnut; keep it on the fire about half an hour longer, and it
is ready to bottle for use.
(20) J. T. S.--Engines with automatic cut-offs will run steady with
variable work. If you have a governor that only controls a throttle
valve, there will be a small variation of speed with as much variation
in the work as you state. Much depends upon the relative amount of work
absorbed by the mill and the variable machinery.
TO INVENTORS.
An experience of forty years, and the preparation of more than one
hundred thousand applications for patents at home and abroad, enable us
to understand the laws and practice on both continents, and to possess
unequaled facilities for procuring patents everywhere. A synopsis of
the patent laws of the United States and all foreign countries may be
had on application, and persons contemplating the securing of patents,
either at home or abroad, are invited to write to this office for
prices, which are low, in accordance with the times and our extensive
facilities for conducting the business. Address MUNN & CO., office
SCIENTIFIC AMERICAN, 361 Broadway, New York.
INDEX OF INVENTIONS
For which Letters Patent of the United States were Granted
February 8, 1887,
=AND EACH BEARING THAT DATE.=
[See note at end of list about copies of these patents.]